The manufacturing method of a keypad for a contact of character illumination rubber switch made by rubber, which illuminates only either characters or figures, is already well known through the Japan Patent Publication No. HEISEI 5-32850. In this method, a laser beam is irradiated so that the laser beam energy is absorbed into a colored surface layer in the shapes of characters and burns the layer off it.
In order to remove the colored surface layer by means of the laser beam it is necessary to arrange materials such as carbon black on the surface so that the laser beam is readily absorbed into the colored layer. Therefore the available keypads manufactured by irradiating laser beam currently have only dark colors such as black or gray or the like as the colored surface layer. It is possible to emit the laser beam on the colored surface layer of any colors which are not black or gray and to burn it off it. However, the incomplete removal thereof is readily caused within the colored surface layer because the colored surface layer do not completely absorb the laser beam. Moreover, if by increasing the irradiation dose of the laser beam the colored surface layer is removed, removal or burning thereof is caused on the lower colored light permeable layer. Accordingly, by using such a laser beam unit, it is difficult to obtain high quality products and successful marketing of the product can not be realized